According to a story on the Renal Fellow Network, rituximab has emerged in recent years as an effective therapy for ANCA-associated vasculitis (AAV). This is a group of autoimmune diseases that often include the involvement of the kidneys. This therapy acts uses multiple mechanisms to intervene in this illness. This story covers an overview of the clinical trials that demonstrated the effectiveness of the therapy as a treatment for this illness.
About ANCA-Associated Vasculitis
ANCA-associated vasculitis is a group of diseases that are characterized by the damage and destruction of blood vessels as a result of inflammatory activity. The disease is associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA). These are autoantibodies that target antigens present on neutrophils (the most common type of white blood cell) and monocytes. This means that the mechanism of the disease is autoimmune, in which the body’s own immune system mistakenly attacks healthy body tissue. Symptoms of ANCA associated-vasculitis include kidney inflammation, fever, weight loss, abdominal pain, bloody stools, purpura, nose bleeds, muscle pain, arthritis, bloody cough, vision problems, headaches, stroke, heart attack, and high blood pressure. Treatment of the disease is primarily focused on controlling inflammation and suppressing immune system activity. Common medications include cyclophosphamide, rituximab, and prednisone. Antibiotics may be necessary in cases of infection. To learn more about ANCA associated-vasculitis, click here.
Clinical Trials: Induction Therapy
The drug was first evaluated as a therapy to induce remissions in the 2010 RITUXVAS and RAVE trials. The RITUXVAS trial results were not encouraging, with slightly less promising performance from rituximab in this role when compared to cyclophosphamide. However, the RAVE trial found that rituximab was not inferior to cyclophosphamide, and seemed to have some advantages in efficacy for patients with relapsed disease.
Clinical Trials: Maintenance Therapy
The remaining trials evaluated rituximab as a maintenance therapy. The first of these was MAINRITSAN in 2014. The results of this trial demonstrated the superiority of rituximab as a maintenance treatment in comparison to azathioprine. MAINRITSAN 2, which took place in 2018, attempted to establish a tailored dosing regimen but found no significant difference when attempting the new regimen.
The RITAZAREM trial in 2019 was an open-label study that once again compared rituximab and azathioprine in the maintenance therapy role. These patients were treated with an induction of rituximab and glucocorticoids, which was different from MAINRITSAN, in which induction took place with cyclophosphamide. Once again, the patients that received rituximab were less likely to experience relapse.
MAINRITSAN 3 (2020) attempted to establish what the best duration for rituximab maintenance therapy would be. This involved a longer treatment period than had been used in the other studies. At 28 months, the treatment allowed the vast majority of patience to continue relapse-free, and rituximab again demonstrated its superiority in comparison to other maintenance therapies.
Overall, rituximab can perform well as induction and maintenance therapy for people living with ANCA-associated vasculitis. In induction, it can allow for patients to avoid the toxicity associated with cyclophosphamide; however, there are cases in which cyclophosphamide should be selected over rituximab.
